1. Technical Field
The present disclosure relates generally to the production of butadiene sulfone from reaction of butadiene and sulfur dioxide, and more particularly to apparatus and methods for producing butadiene sulfone via liquid phase (4+1) cycloaddition between butadiene and sulfur dioxide. More specifically, the disclosure relates to the reduction of mass transfer limitations in apparatus and methods for converting sulfolene to butadiene sulfone.
2. Background of the Invention
The present disclosure relates to the production of butadiene sulfone, also known as sulfolene. Sulfolene is a cyclic monosulfone that is used as a chemical intermediate for many industrially significant products such as pure butadiene. Additionally, sulfolene can be readily hydrogenated to sulfolane, which is a valuable selective solvent for many organic substances, as well as a thermally stable inert reaction medium.
Conventionally, the method for preparing sulfolene includes mixing a significant molar excess of liquid butadiene, with liquid sulfur dioxide under non-aqueous conditions. During this method the reactants are mixed at pressures between 100 and 500 pounds per square inch and at a temperature of about 100° C. In certain cases, a substituted diene may be used. However, the reaction times for this conversion are considered excessively long, and can be as high as two days. Furthermore, sulfur dioxide and butadiene in this conventional processes form insoluble polymeric butadiene sulfones; generally those conditions which increase the reaction rate for the sulfolene reaction also increase the rate for the undesirable polymer reaction. Research and development has primarily focused on the development of systems to prevent the formation of the polysulfones.
For example, a process of applying polymer inhibitors to prevent formation of the polysulfone has been disclosed in U.S. Pat. No. 2,443,270. Sodium hydroxide washing of the butadiene to eliminate peroxides, which favor the formation of polymer, has been disclosed, for example in U.S. Pat. No. 2,420,834. Other conventional techniques have strived to improve results by controlling the temperature of the reaction, for example, U.S. Pat. Nos. 2,402,891 and 2,395,050. Other procedures describe the preparation of sulfolene in alcohols or other organic substances, for example, U.S. Pat. No. 3,077,479 and German Pat. No. 506,839.
Accordingly, there is a need in the industry for improved processes for the production of butadiene whereby effective conversion is obtained. For example, systems for sulfur dioxide and butadiene conversion to butadiene sulfone are desired; with reduced costs, improved characteristics such as, yield, temperature, pressure, reaction time, and/or reduced capital and/or operating costs.